How many of you have ever thought about making a model train layout without a super cool bridge somewhere? I bet that answer is close to zero!
But knowing how to build a model train bridge is another story altogether. What style bridge should it be? What materials should I use? How stable should it be? Is my train too heavy? All of these are great questions!
But not to worry. Just follow our guide and you’ll learn how to build a model train bridge in no time.
Why build a bridge for your model train layout?
Now, why should you build a bridge for your model train layout? Simply imitating the real-life scenario of railroad bridges and adding some variety to your model train layout goes a long way to increasing the immersion. Plus, it’s super fun!
You can build one to make it go over a tread, to go over another train, or go over a river.
There’s nothing that makes a model train layout look better seeing your rolling stock approach a valley before heading over a small river and making it safely to the other side.
By also having multiple levels, you’re also increasing the possibility of having even more trains running around an especially tight layout!
A brief history of train bridges
The history of the railway bridge is long, and we just don’t have the time or space to cover it all here, so let’s just run through a quick history!
The oldest railway bridge still in continual use was built all the way back in 1825; The Skerne Bridge in Darlington UK! This bridge is effectively a small aqueduct bridge, with a single arch.
Ever since then, railway bridges had gone through many iterations by engineers over the years, and many different bridges have been invented, each with their own specific purpose.
We’ve had bridges made like the Trestle bridge; this bridge focused on evenly distributing the weight of the load while it passes across safely. It was used by almost all railways for much of the 19th and 20th centuries, especially in the USA.
Next up was a Trestle bridge, which used triangle trusses to form compression and tension to help keep the bridge upright. It was an incredibly economic bridge to make and eventually helped phase out most of the trestle bridges.
Next in line was the Cantilevers bridge. It is a colossal version with many of the same principles of a truss bridge but allows for construction at a much larger scale.
Now despite having a shaky history, we have giant Suspension bridges like the Tsing Ma bridge in Hong Kong, that used large cables to help hold it up – this bridge extends 1,377m long across two islands.
A little bit bigger than the Skerne Bridge, which must be no more than 15m across!
What types of bridges are there?
There are many types of bridges now made for railroads. Here are the seven main types of bridges used in railroads.
- Trestle Bridge
Trestle bridges were one of the first types of bridges made for railroad use. This type of bridge works by evenly distributing the weight of the train to its whole structure. It would use tens or even hundreds of individual trestles below the bridge to help support the train overhead.
- Truss Bridge
A Truss bridge was really the next iteration of a bridge that came about and used triangle shaped truss’s overhead to help hold the bridge in place using tension and compression. Because it used far less material than a typical trestle bridge, its economic benefit saw a lot of trestle bridges being replaced.
- Cantilever Bridge
Cantilever bridges are built with the same principle as truss bridges but the structure is different. You have a pillar that serves as the anchor of supporting a horizontal deck that stretches out both ways. Multiple pillars holding the deck distribute the weight evenly and use what’s known as a cantilever to help hold the bridge upright.
- Arch Bridge
The arch bridges work by distributing the load of themselves and whatever it carries to the corners in two keystones. These are probably the oldest ‘bridges’ in existence, and the principal dates back to ancient aqueducts.
- Suspension Bridge
The suspension bridges are the most popular bridges around the world. One of the most notable suspension bridges is the Golden Gate Bridge in San Francisco, USA.
These types of bridges use vertical pillars and use it to leverage the weight of the bridge with suspension cables. It is essentially like hanging the bridge on the cables from the pillars.
- Tied-Arch Bridge
Ties-arch bridges use the principle of a suspension bridge, mixed with an arch bridge.
The corners are constructed with the mechanics of an arch bridge. The centre/ middle uses suspension wires like the suspension bridge to carry the load. While they look great, they’re not super structurally sound, so definitely not train friendly.
- Cable-Stayed Bridge
A cable-stayed bridge is in a very similar way to a suspension bridge. While a suspension bridges’ cables pass through the tower and are connected to the bridge, with a cable-stayed bridge, the cables are firmly affixed to the tower itself.
- Beam Bridge
The beam bridges are one of the simplest bridges out there. This type of bridge uses beams to support the load of the bridge. There is no even weight distribution necessary. If you’re looking to make something quick and dirty for a model train layout, this is probably the bridge to go for.
What is Bridge Load Support?
So we’ve taken a look at the different types of bridges out there, and hopefully, by now you’ll have a little idea in your head about the type of bridge you might want to put into your model train layout.
But what about bridge load support? Which is a fancy way of saying how much weight can the bridge take!
There are two types of loads for a bridge; One is the dead load and the other is the live load.
The dead load is the weight of the bridge and everything that it encompasses. A bridge needs to be strong enough to effectively hold itself up at a bare minimum.
The live load is what it carries, so your model train and all its cargo.
The beams, cables or any structure of the bridge that supports the load is called load support.
How to Build a model train bridge to your layout?
Now we come to our most important discussion. How to build a model train bridge!
Honestly, so long as you have an idea in mind, and your bridge is going to have enough load support so that it doesn’t collapse under the weight of your train, you can do just about anything.
You could even use Lego basic bricks, but that might look a little childish. But they do make great internal supports, provided you do up the outside.
So for the most realistic look, we’d recommend you use popsicle sticks or balsa wood for making the bridge. They’ll look the most realistic, especially after some weathering.
Here’s Model Railroad Academy talking about setting up the layout correctly to put a bridge into!
The next step really depends on the type of bridge you want, but the part that’s required for all bridges is the section that your train will travel over. Grab some balsa wood, cardboard or heavy foam and get to work cutting, glueing and carving until you’re happy with how it looks. Obviously, it’s a great idea to use references for this step.
Next depends on the type of bridge you’re making. For a trestle bridge, you need to spend time making tons and tons of trestles, then attack them to the base of the bridge.
Alternatively, if you’re making a truss bridge or something with a tower, try and get an orthographic side-on view, then print it out, so you can build right on top of it before attaching it to the base
Take a look at Luke Towan building a simple trestle bridge here for a more visual look!
So that is how you can make a railway bridge for your model train. If you want it to be more stable, you can use cement and small pebble stones to make the bridge.
The more creative you get with it, the more realistic and awesome it will look.
Peter has been building model trains for longer than he can remember. An avid fan of HO and O scale this blog is a creative outlet to allow him to dive further into other scales and aspects of the model train community and hobby.